The invention refers to an aid for wearing the hard corneal contact lenses commercially available on the eyeballs.
If a soft contact lens does not yield sufficient visual acuity because it adapts to the deformed cornea, it is necessary to use a hard contact lens instead of a soft one. However, the hard contact lens is not compatible enough in many cases, since it causes pressure sores and abrasions on the outward parts of the cornea, or it does not align centrally on the cornea.
There is already a corneal contact lens known, which is made of hydrophil plastic gels, in the center of which there is an adaptor of hard plastics is pasted, cemented or welded. Such contact lenses must have a certain minimum thickness at their junction, which, however, is too high for most applications. They will easily break at the junction, causing an injury hazard for the cornea, tending to develop pressure sores, eye redness and hypometabolism. Apart from this, it is hardly or even not at all possible to connect the central solid plastics with the outward soft plastics.
It is much more advisable to manufacture soft contact lenses whose central optical part is stiffer. However, in practice such lenses are not used since there are unsolvable problems connected to them. For instance, they will deform on the eye because the central part is not quite hard enough.